1973 Evinrude 65ph - Starts on 2 cylinders

I've been working on my 73 65ph Evinrude. It sat for about 5 years. I've rebuild the carbs, replaced the impeller, de-carbed the heads/carbs with Seafoam. Compression test on all three cylinders 90 psi before de-carb it. I should do another compression test but haven't yet. I haven't adjusted the timing. The engine takes a while to start and runs ruff at idle. There was little change before and after the carb rebuild. On the lake when I increase the power it hesitates (some times for 30 sec to a minute) and than kicks in (seems like its running on 2 cylinders than the third kicks in) Once that happens it runs fine the rest of the time. Question: What would cause the engine to hesitate when cold and then suddenly kick in?

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

Try a cyl drop test on it when it is acting up. That way you can narrow it down to any one cyl.

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

Ninety psi is kind of low for that engine. I would do another compression test, just to be sure. Ideally, you should see between 130 and 150 psi. Given its age, however, 150 psi is a long shot.

On the carb rebuild, did you remove the HS orifices from each of the carbs? If not, you could still have junk in one of them.

If you think the problem is ignition related, I find an easy way to see exactly what is going on, is to use an inductive timing light, while it is running. The sensor lead can be placed on each spark plug wire, one at a time, to see what is going on. By taping the trigger on the gun shut, you can observe what each ignition circuit is doing. You should see steady flashing of the light - if you are getting intermittent flashing, you have a problem. Such a condition could be related to the timer base, powerpack or ignition coil for that cylinder.

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

Thanks for the advice. I started the engine and pulled the plugs one at a time. Top cylinder, is operating OK,Plulling plug the engine would keep running. Middle cylinder, after pulling plug would stop the engine and third cylinder, didn't seem to make a difference if the plug was on or off the spark plug.
How can I determine what the root cause is at this point? (Coil, timer, powerpack)
Any advice would be greatly appreciated!

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

You're pulling the plug or the plug wire? You should have a drop in RPM after a couple seconds of pulling the plug wire. If not you need to start your troubleshooting at the plug that's not firing and work your way to the ignition.

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

Get a spark tester at your local parts house ($ 10.00 ) and run an open air gap cranking test. Spark should jump a 7/16 " open air gap on all cyls. If not you have ignition probs.

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

Oh boy and ignition parts or quite costly on those babies too

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

He has to narrow it down to the problem some how. Checking the spark other than compression should be some of the first steps.

Re: 1973 Evinrude 65ph - Starts on 2 cylinders

Sounds like the #3 ignition circuit is your problem. You can confirm by putting the lead back on the plug and using an inductive timing light. If you get no flashing of the light, or unsteady flashing, you have a problem.

First, be sure that the spark plug is good. You could also have problems with the corresponding ignition coil, the high tension lead, the power pack or the timer base.

One common problem with the original coils, is that the high tension leads are screwed onto a small post in the recessed insert point on the coil. Sometimes the wire comes loose. If this is the case, trim about a 1/4 inch off the end of the wire and screw it back into the coil. Then seal with some silicon. On the opposite end of the wire, check to see if the wire coil that is in the boot is properly mounted to that end of the high tension lead. They sometimes come loose.

If you suspect an ignition coil, the easiest way to confirm that as a problem, is to simply swap it from one of the ignition circuits that is known to be good. For example, swap the #2 and #3 coils. Be sure to swap the leads that go to the power pack, when you do this. If its a coil problem, the failed circuit should now be the #2 (you swapped what was the #3 coil to it).

If the problem stays with the #3 cylinder, the ignition coil is not your problem and the suspect items become the power pack or timer base. Read the thread below, for advice on checking them. It is in regard to a '73 model, but the ignition system is the same.


http://forums.iboats.com/showthread.php?t=525954&p=3572299#post3572299